Toyota GR Supra Races Into 2021 with More Power and First-Ever Four-Cylinder Turbo Model

[harddrivin1le]

There is no point with the 6 port manifold. B58c has a sort of inbuilt (into engine block) manifold to 2 ports, so both ports can connect directly to the twin scroll turbo. It is actually the better more efficient design...

Why doesn't the highest output B58 variant (S58, as used in the M3/M4) use "the better more efficient design?"

And why would BMW even bother with the 6 external port configuration if they could simply crank up the boost (as so many 2020 Supra owners do through "tunes") to achieve the same and even higher output levels?

Source: BMW Tech training manual
https://www.bimmerpost.com/goodiesforyou/docs/ST1926-S58-Engine.pdf

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[John8]

I don't plan on changing my 2020 but enjoy reading here as I used to rebuild and enjoyed it, with my first rebuilt a Corvair leaky engine I had in a VW bus! That thing flew and confounded people. lol But I didn't know much of what I was doing but it was fun and all I had was a manual and no real help. Anyway, remember the 2021 is heavier so that is why they needed more HP. :^)

 

[harddrivin1le]

I don't plan on changing my 2020 but enjoy reading here as I used to rebuild and enjoyed it, with my first rebuilt a Corvair leaky engine I had in a VW bus! That thing flew and confounded people. lol But I didn't know much of what I was doing but it was fun and all I had was a manual and no real help. Anyway, remember the 2021 is heavier so that is why they needed more HP. :^)

Toyota claims the 2021 Supra is just 3 pounds heavier than the 2020 version (inline six version vs. same):

https://pressroom.toyota.com/toyota...wer-and-first-ever-four-cylinder-turbo-model/

This 2020 BMW M340i is a whopping 455 pounds heavier than the Supra in the link below and uses the same engine as the 2021 Supra.

https://www.caranddriver.com/reviews/a30143002/2020-bmw-m340i-reliability-maintenance/

2020 Supra:
https://www.caranddriver.com/reviews/a27440454/2020-toyota-supra-by-the-numbers/

Both cars were tested by the same magazine (consistency in testing methodology).

Despite being 455 pounds heavier (152 times heavier than 3 pounds) , the BMW M340i posted the same 12.3 second ET as the 2020 Supra, but was actually 2 MPH faster (trap speed)!

Hale's formula tells us that the 2021 Supra should therefore trap in the 118 MPH region, which is some 5 - 6 MPH faster than the 2020 model.

That translates into a substantially faster Supra for 2021, particularly as elevated speeds.

 

[John8]

Toyota claims the 2021 Supra is just 3 pounds heavier than the 2020 version (inline six version vs. same):

https://pressroom.toyota.com/toyota...wer-and-first-ever-four-cylinder-turbo-model/

This 2020 BMW M340i is a whopping 455 pounds heavier than the Supra in the link below and uses the same engine as the 2021 Supra.

https://www.caranddriver.com/reviews/a30143002/2020-bmw-m340i-reliability-maintenance/

2020 Supra:
https://www.caranddriver.com/reviews/a27440454/2020-toyota-supra-by-the-numbers/

Both cars were tested by the same magazine (consistency in testing methodology).

Despite being 455 pounds heavier (152 times heavier than 3 pounds) , the BMW M340i posted the same 12.3 second ET as the 2020 Supra, but was actually 2 MPH faster (trap speed)!

Hale's formula tells us that the 2021 Supra should therefore trap in the 118 MPH region, which is some 5 - 6 MPH faster than the 2020 model.

That translates into a substantially faster Supra for 2021, particularly as elevated speeds.

3 Pounds! That kills the deal for me. lol It was a joke. But frankly, the extra power, for my enjoyment of doing curves etc., isn't needed. For fun though, I may buy the front strut tower supports. Not the ones shown on the BMW, that look like someone made them in shop class or in 10 minutes in the garage though they, functionally wold perform as well but look like shit.

 

[harddrivin1le]

3 Pounds! That kills the deal for me. lol

And remember that those 3 pounds include the "aluminum braces that tie the strut towers to the radiator support to increase lateral rigidity," per Toyota's press release.

I was admittedly disappointed by the 2020 car in some respects. Having said that, the 2021 version will likely result in my purchasing one (though perhaps not until the 2022 model year).

 

[hanswurst24]

One wonders what those regulations are, given that the BMW M340i uses the very same same engine as the 2021 US market Supra, yet is sold in Europe. While the Z4 M40i uses a very slightly different variation (higher compression ratio and presumably less peak boost), it's also sold in Europe.

Why would those engines meet European regulations when installed in BMWs, but not meet them if installed in the Supra?

It's not only the engine (think about OPF, etc. everything behind the engine's exhaust manifold and behind the turbo)
The B58B30M1 (B58C as Toyota calls it) in the European Supra and Z4 is used because emissions regulations and packaging problems. You are right: the B58B30O1 (B58D as Toyota calls it) is used in other BMW cars here in Europe, but with additional hardware to meet the emissions regulations.
The story BMW told us (last year), the Z4, because of its platform, has a packaging problem and therefore will not recieve the O1 variant (and guess which car shares the platform with the Z4 ^^ ).
So for now, Europe won't get the O1. But never say never and it will be interesting to see what they will do with the GRMN version in a few years.

On the plus side: European tuners will still be supporting the M1 variant for quite some time.

 

[Axix23]

We can debate this to death and speculate this and that but until we can get a 2021 and run it against a 2020 and dyno it. We won't know anything but speculate..

 

[Reppunkamui]

Why doesn't the highest output B58 variant (S58, as used in the M3/M4) use "the better more efficient design?"

And why would BMW even bother with the 6 external port configuration if they could simply crank up the boost (as so many 2020 Supra owners do through "tunes") to achieve the same and even higher output levels?

Read and comprehend the conversation... EastCoastSupra wanted Toyota to provide him the manifold for his/her 2020 Supra. I told him it won't fit unless his engine block was changed.

Other statements have been dealt with to death... with yourself ignoring/misconstruing responses whilst berserking on imaginary strawmen.

 

[KahnBB6]

Read and comprehend the conversation... EastCoastSupra wanted Toyota to provide him the manifold for his/her 2020 Supra. I told him it won't fit unless his engine block was changed.

Other statements have been dealt with to death... with yourself ignoring/misconstruing responses whilst berserking on imaginary strawmen.

Hang on... if I understand your post correctly then the MY2021 6-port cylinder head *will not* fit on a MY2020 B58 engine block that originally came with the cylinder head that has an integrated exhaust manifold cast into it.

So not only are 2020 and 2021 cylinder heads different (which we knew already) but the 2020 and 2021 B58 *lower engine blocks* (ie: the "short block" assemblies only) are also different?

Is that correct?

 

[Reppunkamui]

Hang on... if I understand your post correctly then the MY2021 6-port cylinder head *will not* fit on a MY2020 B58 engine block that originally came with the cylinder head that has an integrated exhaust manifold cast into it.

So not only are 2020 and 2021 cylinder heads different (which we knew already) but the 2020 and 2021 B58 *engine blocks* are also different?

Is that correct?

Yes. you are absolutely correct.

The 2020 Supra has 2 exhaust outlets out of the engine block which bolts directly onto the twin scroll turbo.

 

[harddrivin1le]

Read and comprehend the conversation... EastCoastSupra wanted Toyota to provide him the manifold for his/her 2020 Supra. I told him it won't fit unless his engine block was changed.

Other statements have been dealt with to death... with yourself ignoring/misconstruing responses whilst berserking on imaginary strawmen.

Oh, I read and comprehend everything.

The primary reason the new manifold won't fit is because the 2020 Supra uses a 2 (vs. 6) exterior port cylinder head. I've posted the related illustrations yet again for your convenience. On the left we see the 2020 "2 port" setup, while on the right we see the 2021 6 port set-up. Regardless of the "block," there's no way the 6 port exhaust manifold would mate up to the 2 port head!

Now tell us all again about how much "more efficient" the 2020 Supra's 2 port exhaust system is, relative to the 2021's 6 port system.

Be sure to elaborate on "aluminum" for no discernible reason, given that both variants utilize an aluminum head and steel exhaust manifold.

Also be certain to ignore THE K FACTOR in compressible flow, per the engineering link I provided.

Oh, I should have also mentioned that heads such as the 2020 Supra's RUN HOTTER because the exhaust (especially from the other most pistons) remains in the head for longer periods of time when traveling to the 2 (as opposed to six) exterior exhaust ports. I'll also that engine coolant tends to also run hotter in such a configuration. All of this increases combustion chamber temperatures, which in turn mandates lower peak boost levels.

BOTTOM LINE: The 2020 Supra's engine was a cheap solution to more complex problem. Compromises were knowingly made accordingly. Toyota addressed these issues in the 2021 Supra by adopting BMW's M340i engine, which of course uses a more elaborate split cooling system and a cylinder head with six exterior exhaust ports, which in turn mates up the 6 (vs. 2) runner exhaust manifold.

 

[harddrivin1le]

Yes. you are absolutely correct.

The 2020 Supra has 2 exhaust outlets out of the engine block which bolts directly onto the twin scroll turbo.

The 2 exhaust outlets are in the cylinder head (not the block).

The 2021 6 exhaust outlets are also in the cylinder head, not the block.

Its impossible to use the 2021 6 port exhaust manifold in the 2020's 2 port cylinder head and vice-versa.

The last time engine I'm aware of that used exhaust valves I the block was the old flathead Ford.

The 2 port cylinder head is depicted on the left of the attachment, with the 6 port on the right.

I've also added a generic engine illustration to demonstrate the difference between a cylinder head and a block.

 

[Reppunkamui]

My last post on this, just to show previous answers (earliest post is used since I repeated multiple times).

Oh, I read and comprehend everything.

The primary reason the new manifold won't fit is because the 2020 Supra uses a 2 (vs. 6) exterior port cylinder head! I've posted the related illustrations yet again for your convenience.

Now tell us all again about how much "more efficient" the 2020 Supra's exhaust system is, relative to the 2021's.

I was talking about mechanical and manufacturing design being better and more efficient (not exhaust flow, which is not clear to me in stock form).

- better fuel consumption (faster engine warm up)
- less weight, aluminium vs steel.
- cheaper, exhaust manifold connecting 6 ports to turbo not required.
- more reliable - 2 seal/gaskets vs 8.
- simpler disassembly or change.

As mentioned previously, the exhaust manifold has its advantages too, since it is steel it is stronger and can handle higher pressure and heat. Also, can be swapped for aftermarket. I.e. overall better for mods.

Be sure to elaborate on "aluminum" for no discernible reason, given that both variants utilize an aluminum head and steel exhaust manifold.

Aluminium is lighter than steel. Internal manifold is aluminium alloy of the engine block, vs the steel of the exhaust manifold.

Also be certain to ignore THE K FACTOR in compressible flow, per the engineering link I provided.

As mentioned, I can't be sure about the flow, since to me it purely depends on the piping design of the internal manifold vs the steel manifold. Same size connections from cylinder to manifold and from manifold to turbo. B58M1 is an improvement over the B58M0 with more power, adding an exhaust flow restriction seems like an odd decision.

Oh, I should have also mentioned that heads such as the 2020 Supra's RUN HOTTER because the exhaust (especially from the other most pistons) remains in the head for longer periods of time when traveling to the 2 (as opposed to six) exterior exhaust ports. I'll also note that engine coolant tends to also run hotter in such a configuration. All of this increases combustion chamber temperatures, which in turn mandates lower peak boost levels.

- better fuel consumption (faster engine warm up)

BOTTOM LINE: The 2020 Supra's engine is a cheap solution to more complex problem. Compromises were knowingly made accordingly. Toyota fixed this in the 2021 Supra by adopting BMW's M340i engine, which of course uses a more elaborate split cooling system and a cylinder head with six exterior exhaust ports, which in turn mate up the 6 (vs. 2) runner exhaust manifold.

As mentioned previously, the exhaust manifold has its advantages too, since it is steel it is stronger and can handle higher pressure and heat. Also, can be swapped for aftermarket. I.e. overall better for mods.

Apologies, there are 2 questions you asked earlier that I did not respond to:

What do you mean by "2 seal/gaskets vs 8?" In all likelihood, both engines use a single gasket to make the exhaust manifold to the head.

There are 2 connection points on the B58c connecting to the turbo. There are 6 connection points from the B58d to the manifold and 2 more between the manifold and turbo. Likelihood not required, it is in the assembly diagrams for both engines.

What does "simpler disassembly or change" mean? Please quantify that..

If we wish to change or replace the cylinder head or the turbo, we do not have to deal with as many flanges/bolts. The engine bay does not have alot of space for work.


Closing statement, once again lets just agree to disagree, because this is going nowhere.

Also, I am used to referring to the engine block including the cylinder head and crankcase. But I can understand that this is not technically correct and apologise if this caused confusion.

*edit* I think I recognise a difference in our baseline which may be part of the confusion. I do not consider B58c has a steel exhaust manifold because it bolts straight to the turbo (effectively the exhaust manifold is internal as part of the aluminium cylinder head). You consider the B58c has a steel 2 port exhaust manifold.

 

[harddrivin1le]

The cylinder head is a completely separate item from the block. That's been widely accepted fact for more than half a century.

Both the 2020 and 2021 Supra inline 6 engines use aluminum cylinder heads and external steel exhaust manifolds. There is no difference in that regard, thereby rendering your belaboring of the issue entirely moot.

You clearly have no understanding of compressible flow fluid dynamics, including bend radii and the K factor. As such, you're in no position to have any legitimate opinion on the matter.

https://www.pipeflowcalculations.com/pipe-valve-fitting-flow/compressible-gas-flow.xhtml

https://www.highpowermedia.com/Archive/category/exhausts/tight-bends
Excerpt: Without being able to specify what is too tight a bend, we can make some generalizations and the obvious one is not to use very tight bends unless absolutely necessary."

BMW engineers specify the 6 port head/manifold combination in the highest performance B58 variant, the S58. That alone should be enough for any rational person to see that's the superior arrangement. They'd use "the more efficient" (your words) 2 port arrangement with the (partial) manifold in head were that not the case.

The 2020 Supra's 2 port set-up is cheap solution that compromises overall engine efficiency. That's why Toyota dumped in in the 2021 Supra upgrade. If you want the better engine in a Supra, you'll need to sell your 2020 and buy a 2021.

 

[harddrivin1le]

...Also, I am used to referring to the engine block including the cylinder head and crankcase. But I can understand that this is not technically correct and apologise if this caused confusion.

This is what an engine that has the heads in the block looks like. There is no individual cylinder head.

Ford hasn't built such an engine since 1953, 67-68 model years ago.

In no way does a modern automobile engine (overhead valve in head configuration) cylinder head "include the crankcase." Indeed, you're the first person I've ever encountered who's made such a claim in all of my years on this planet.

Why not claim that the cylinder head also includes the crankshaft, pistons, rods and oil pan?

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